Problem: Simplify the following expression: $7\sqrt{275}$.
Explanation: First, try to factor a perfect square out of the radical. $= 7\sqrt{275}$ $= 7\sqrt{25 \cdot 11}$ Separate the radical and simplify. $= 7\sqrt{25} \cdot \sqrt{11}$ $= 7 \cdot 5 \cdot \sqrt{11}$ $= 35\sqrt{11}$